Blondie Recipe UK: Chewy, Buttery White Chocolate Bars

A blondie is a chewy, buttery traybake with the soft, dense texture of a brownie, but flavoured with brown sugar and vanilla instead of cocoa. This UK-friendly recipe uses easy-to-find ingredients, white chocolate and a little salt for balance; the key is to take it out while the centre is just set so it stays fudgy as it cools.

Ingredients

¾ cup (170 g) unsalted butter, plus a little extra for greasing the tin
1 cup packed (200 g) light brown soft sugar
¼ cup (50 g) caster sugar
2 large eggs, at room temperature
2 teaspoons (10 ml) vanilla extract
1¾ cups (220 g) plain flour
½ teaspoon fine salt
½ teaspoon baking powder
¾ cup (130 g) white chocolate, roughly chopped, or white chocolate chips
½ cup (60 g) toasted pecans or walnuts, roughly chopped (optional)

Instructions

Heat the oven to 350°F (180°C), or 320°F (160°C) fan. Lightly grease a 20 cm (8-inch) square baking tin and line its base and sides with baking paper, leaving a little overhang to lift out the blondies later.
Melt the butter in a small saucepan over low heat, then take it off the heat. Stir in both sugars until evenly combined. Let the mixture cool for about 5 minutes; it should feel warm, not hot, so it does not scramble the eggs.
Whisk the eggs and vanilla into the butter mixture until smooth and glossy. In a separate bowl, stir together the flour, salt and baking powder. Add the dry ingredients to the wet mixture and fold gently with a spatula just until no dry flour remains. Avoid beating the batter, which can make the bars tough.
Fold in the white chocolate and, if using, the nuts. Scrape the batter into the prepared tin and spread it into an even layer, taking it right into the corners.
Bake for 23–27 minutes, checking from 23 minutes. The edges should look lightly golden and set, while the middle remains a little soft; a skewer inserted near the centre should come out with moist crumbs, not liquid batter. Do not wait for a completely clean skewer, as the blondies will continue to firm up as they cool.
Set the tin on a rack and leave the blondies to cool completely, about 60 minutes. Lift them out using the paper and cut into 16 squares with a sharp knife. For neater slices, wipe the knife between cuts.

Tips

Measure the flour carefully. For the most reliable result, use the gram weight. If using cups, spoon flour into the cup and level it rather than packing it down; too much flour makes blondies dry and cakey.
Choose the right tin. A 20 cm (8-inch) square tin gives the stated thickness and timing. A larger tin makes thinner blondies that bake faster, so begin checking early; a smaller tin needs more time and may brown before the centre sets.
Keep the mixing gentle. Once the flour goes in, fold only until combined. Overmixing develops gluten and can make the texture chewy in the wrong way rather than soft and fudgy.
Let them cool before cutting. Warm blondies are fragile and may seem underbaked. They set as they cool, so judge doneness by the gently set edges and moist crumbs rather than trying to cut them straight from the oven.

Serving Suggestions

Serve the squares at room temperature with tea or coffee, or warm one briefly and add a scoop of vanilla ice cream for dessert. Fresh raspberries or sliced strawberries give a sharp, fruity contrast to the sweet white chocolate. For a simple finish, dust the cooled slab lightly with icing sugar just before serving.

Variations

For a less sweet bar, replace the white chocolate with the same weight of milk or dark chocolate; the flavour will be richer and less creamy. For a nut-free version, simply leave out the pecans or walnuts, or replace them with an extra 60 g (about ⅓ cup) of chocolate. A teaspoon of finely grated orange zest folded into the batter works well with white chocolate. You can also add ½ cup (75 g) dried cranberries for a tart, chewy note. Keep additions to roughly the same volume so the batter still bakes evenly.

Storage and Reheating

Cool the blondies fully, then store them in an airtight container at room temperature for up to 4 days. Refrigerate them if your kitchen is very warm, though chilling makes the texture firmer; bring portions back to room temperature before serving. For longer storage, freeze individual squares in a sealed freezer-safe container for up to 3 months, separating layers with baking paper. Thaw overnight in the refrigerator or for a few hours at room temperature. To serve warm, microwave one square for about 10–15 seconds; avoid overheating, which can make the chocolate too hot and the bar dry. Refrigerate within 2 hours if they are being kept chilled, and discard any that have been left out for longer than 2 hours in a hot environment.

Frequently Asked Questions

How do I know when blondies are done?
Look for set, lightly golden edges and a centre that is still slightly soft. A skewer should have moist crumbs clinging to it, but no runny batter. The middle firms as it cools, so baking until the skewer is completely clean can leave the finished bars dry.

Why are my blondies cakey?
Common causes include too much flour, overmixing after adding it, or baking for too long. Weighing the flour and taking the tin out when the centre is just set helps preserve the dense, chewy texture.

Can I make blondies without white chocolate?
Yes. Leave it out for a straightforward brown-sugar blondie, or use the same weight of chopped dark or milk chocolate. Without chocolate, the bars will taste more strongly of caramel-like brown sugar and vanilla.

Can I use a different tin size?
A similar-sized square tin is best. If you use a larger tin, the batter will be thinner and will need less baking time; if you use a smaller one, it will be thicker and need longer. Check early and use the set-edge and moist-crumb signs rather than relying only on the stated time.

Can I make the batter ahead?
For the most even bake, bake the batter soon after mixing. You can bake the blondies a day ahead and store the cooled slab airtight, then cut it before serving. If you refrigerate unbaked batter, it will firm up and may bake unevenly, so it is not the best make-ahead option.

Can I freeze blondies?
Yes. Freeze cooled, cut squares in a well-sealed container for up to 3 months. Thaw them before serving; if you want them warm, heat briefly in the microwave after thawing.

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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

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